Import terraform state

Import AWS resource based on particular tag

We can import our AWS resource base on certain AWS resource attribute or tags using terraformer tools.

To install terraformer you can download binary from https://github.com/GoogleCloudPlatform/terraformer/releases and copy it to your /usr/local/bin or /usr/bin

To import resource EC2, EBS, and security group with tags service=tsidata, you can do the following steps

create terraform provider file in your working dir

echo 'provider "aws"{}' > provider.tf

run terraform init to download aws provider

terraform init

run terraformer command with the following flags

terraformer import aws --resources=ec2_instance,sg,ebs --path-pattern=output --compact=true --regions=ap-southeast-1 --filter="Name=tags.Service;Value=tsidata"

Command above will created directory name output and store the terraform code and terraform state in terraform version 0.12.8
You need to update the terraform_version in terraform.tfstate file to your existing terraform version.
To check imported resource simply run:

terraform state list

Terraformer will create the logical name for each resource based on resource type and the resource name. You still need to adjust this logical name to your existing code.
Notes: You need to use the latest terraformer version to be able to filter resource using its particular attribute or tags, though this will generate terraform state in terraform version 0.12.

Generate terraform state logical name from existing terraform code

run terraform plan on your stack directory,

terraform plan

Copy the output to a file named terraformstate
grep all the terraform state logical name

grep "+" terraformstate

copy the list of logical name, you can use this logical name to replace logical name generated by terraformer tools.
To replace the terraform state logical name run the following command:

terraform state mv <terraformer-generated-state> <existing-code-state-logical-name>l;

Import resource with random id

This is step by step to import terraform resource with random-id

Find out the hex id of the resource name, for example: <service-name>-app-<hex_random_id>
Convert the <hex_random_id> to base64url using this command

echo "<hex_random_id>" | xxd -r -p | base64 | tr '/+' '_-' | tr -d '='

Copy the base64url id, and use it to import the terraform resource with random id

terraform import module.example.random.id <prefix-name>, <base64url>

Please do let me know if something is missing, by replying in the thread of this post.